This invention pertains to the art of strainers and more particularly to fluid strainers.
The invention is particularly applicable to a liquid strainer adapted to be mounted within a strainer housing and will be described with particular reference thereto; however, it will be appreciated by those skilled in the art the the invention has broader applications and may be readily employed in other environments.
Fluid strainer elements are known in the art and have been designed and developed for a number of specific uses. However, none of these prior strainer designs are deemed applicable to or have the necessary physical strength for applications where differential pressures acting on the strainer element may be in the range of 1000 psi. Typically, prior strainers have merely been comprised of a cylindrical core member which provides some strength and rigidity for a straining media which closely surrounds the core.
While many of the prior known strainers merely comprised elongated open ended cylindrical arrangements, some prior strainers did include end walls or caps for closing either one or both ends of the cylinder. Ordinarily, however, these end walls were solid so as to block any fluid flow therethrough resulting in undesirable elevated differential pressures acting on the strainer during use. In addition, liquid passing toward contact with such prior strainers would necessarily hit the closed ends and rebound therefrom so as to cause turbulence in the remainder of the liquid flow. These operational characteristics are extremely undesirable in most applications since they can affect overall operation of an entire liquid system.
Many of the prior strainer designs did not give due consideration to the various types of fluids which the strainers could and/or would be employed. Practical application of the prior strainer designs was, therefore, limited or restricted. Quite often they could not be employed in corrosive or abrasive environments where the temperature of the fluid would be substantially elevated or reduced. This limitation could often be attributed to the fact that many prior strainers were not permanent and were more of a "throw away" type for cost reduction purposes.
It is also known to use sintered metal elements having generally cup-shaped configurations and being manufactured from ceramic or metal materials by powdered metallurgy techniques. Elements formed by such means are classified as filters and may be differentiated from strainers to which the subject invention is directed by a number of functional and structural distinctions. Typically, however, the sintered filters could not be satisfactorily manufactured with particles beyond a certain micron size since, once the sintered particles got much above 90 to 120 microns, the overall structural strength of the filter was substantially reduced so that chipping or breakage during handling and use became a problem. Since the prior sintered elements acted as filters in which virtually all particles in a liquid flowing therethrough were removed, the resistance or restriction to flow through them was quite high. As a result, very high differential pressures were frequently created which, when acting against this type of filter, caused undesired collapsing and complete failure, or caused pressure drop in the system to an undesirable degree.
The present invention contemplates a new and improved article which overcomes all of the above referred to problems and others and provides a new strainer element which is relatively simple in design, can readily withstand high differential pressures, may be employed in any number of different fluid environments including corrosive and abrasive environments and which may be readily backwashed and reused.